V-slat reciprocating slat conveyors

ABSTRACT

Movable conveyor slats ( 12 ) have side parts ( 42, 44 ) which rest on top parts ( 32 ) of bearings ( 30 ). The bearings ( 30 ) have a generally U-shaped cross section and they fit on wings ( 16, 18 ) which extend outwardly and slope upwardly from the sides of a fixed conveyor slat ( 10 ). The movable slats ( 12 ) have web ( 48, 50 ) and lower flange portions ( 52, 54 ) which with the side parts ( 42, 44 ) form laterally outwardly opening channels. The wings ( 16, 18 ) and the bearings ( 30 ) are received within the channels ( 56, 58 ).

TECHNICAL FIELD

The present invention relates to reciprocating slat conveyors. Moreparticularly, it relates to reciprocating slat conveyors composed oflaterally spaced apart, fixed slats, and laterally spaced apart,moveable slats, between the fixed slats, and to an integration of thefixed and movable slats substantially through out their lengths.

BACKGROUND OF THE INVENTION

The present invention is an improvement to the conveyor disclosed byU.S. Pat. No. 5,044,870, granted Sep. 3, 1991, to Raymond K Foster, andto the conveyor disclosed by U.S. Pat. No. 6,848,569, granted Feb. 1,2005 to Raymond Keith Foster. The contents of these patents and thepatents to which they refer are hereby incorporated herein by thisspecific reference. Some features of the invention are the same as orsimilar to features disclosed in co-pending application Ser. No. ______filed ______, and entitled Reciprocating Slat Conveyor with Moving SlatsBetween Fixed Slats (“EP”).

BRIEF SUMMARY OF THE INVENTION

The reciprocating slat conveyor of the present invention comprises apair of laterally spaced apart, longitudinally extending, side beams. Aforward frame section is composed of forward portions of the side beamsand longitudinally spaced apart lateral frame members extending betweenthe forward portions of the side beams. The conveyor also includes arearward frame section comprising rearward portions of the longitudinalside beams and longitudinally spaced lateral frame beams extendingbetween the rearward portions of the side beams. A window is definedlongitudinally between the forward frame section and the rearward framesection. The window provides a space laterally between intermediateportions of the side beams and longitudinally between two longitudinallyspaced apart lateral frame beams. A plurality of drive units areprovided. They include fixed portions connected to the frame and movableportions in the window which are moveable, longitudinally of theconveyor. A like number of transverse drive beams are positioned in thewindow. Each drive beam is connected to the movable portion of a relatedone of the drive units. A plurality of laterally spaced apartlongitudinally extending, fixed slats are connected to the front andrear sections of the frame. The fixed slats bridge longitudinally overthe window and over the transverse drive beams in the window. Aplurality of laterally spaced apart, longitudinally extending, moveableconveyor slats are positioned between the fixed slats. The movable slatsare divided into sets equal number to the number of transverse drivebeams. Each set of movable slats is connected to a separate related oneof the transverse drive beams.

The present invention further comprises the improvement of said fixedslats each having a longitudinally extending center portion and a pairof side wings extending laterally outwardly and sloping upwardly fromthe center portion. Each movable slat has a longitudinally extendingcenter portion, a pair of longitudinally extending side portions, and apair of laterally spaced apart, longitudinally extending hook portions.Each hook portion includes a web connected to its movable slat where thecenter portion meets a side portion. The web of each hook portionextends downwardly and meets and becomes an outwardly directed lowerflange. The side portions of the top, the webs, and the lower flangestogether form laterally outwardly opening channel spaces. Fixed bearingsare provided on the side wings. Each bearing has an upper part sittingdown on its side wing and a lower part below its side wing. The sidewings, and the bearings mounted on them are located in the channels ofthe movable slats, vertically below the side portions of the slats andvertically above the lower flanges of the slats. The side portions ofthe movable slats have bottom surfaces that rest on the upper parts ofthe bearings. The lower flanges of the slats are positioned below thelower parts of the bearings.

Preferably, the fixed and movable slats have uniform cross sectionalshapes throughout their lengths. The fixed slats are connected to thelateral frame members in the forward and rearward sections of the frame.

In a preferred embodiment, the conveyor frame includes a rear frame beamextending transversely of the trailer at the rear of the trailer. Thisrear frame beam includes a top. The movable slats have rear end portionswhich reciprocate forwardly and rearwardly over the top during operationof the conveyor. The rear end portions of the movable slats includeinternal blocks within the rear end portions of the movable slats,between the webs of the hook portions of the movable slats. These blockseach include a longitudinally extending downwardly opening channelspace. Longitudinally extending guide members are secured to the top ofthe rear frame beam. These guide members are positioned to be receivedin the channel spaces of the blocks. As a result, the blocks will slideforwardly and rearwardly along the guide members during movement of themovable slats.

Preferably also, material flow guide members are provided on the top ofthe rear frame beam, behind and in longitudinal alignment with the fixedconveyor slats. Each guide member has a longitudinally extending apexand longitudinally extending side walls which slope laterally outwardlyand downwardly from the apex to the top of the rear frame beam.

Other objects, features and advantages of the invention are here andafter described as a part of the description of the best mode forcarrying out the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Like reference numerals are used to designate like parts throughout theseveral views of the drawings, and:

FIG. 1 is a rear end elevational view of a reciprocating slat conveyorthat forms the bottom of a material compartment, such view showing theconveyor composed of laterally spaced apart fixed slats and laterallyspaced apart movable slats between the fixed slats;

FIG. 2 is a view like FIG. 1, but taken in the region of a transversedrive beam, showing one third of the movable slats connected to thedrive beam;

FIG. 3 is an enlarged scale end elevational view of a first embodimentof the movable slats;

FIG. 4 is a view like FIG. 3, but showing a second embodiment of themovable slats;

FIG. 5 is a fragmentary pictorial view taken from above and lookingtowards the top, rear end and one side of the conveyor, such viewsshowing a fragmentary portion of a rear end frame beam and showingfragmentary rear end portions of the fixed and movable slats;

FIG. 6 is the view of the assembly shown by FIG. 5, but taken frombelow, and looking towards the bottom and front portion of the rear endframe beam;

FIG. 7 is a large scale view of three fixed slats and two movable slats,such view being taken at about in a vertical plane at the forward end ofthe rear frame beam;

FIG. 8 is a view like FIG. 7, but taken looking at the rear end of FIG.5;

FIG. 9 is an enlarged scale fragmentary view of a side wing on a fixedslat and a slide bearing spaced outwardly from the side wing of theslat;

FIG. 10 is a view like FIG. 9, but showing the bearing moved onto theside wing of the fixed slat;

FIG. 11 is an end view of a fixed slat;

FIG. 12 is a view like FIG. 11, but of an outer side fixed slat;

FIG. 13 is an end view of a rear end bearing for the movable slats;

FIG. 14 is a side elevational view of the rear end bearing shown by FIG.13, such view being broken away in its mid portion to indicateindeterminate length;

FIG. 15 is an end elevational view of an end cap for the fixed slats;

FIG. 16 is a side elevational view of a guide member positioned forguiding material discharging rearwardly from the conveyor;

FIG. 17 is an end view of the guide member shown by FIG. 16;

FIG. 18 is a bottom plan view of a fragmentary portion of the conveyorframe and the fixed and moving slats, such view showing a window in theconveyor frame and transverse drive beams and hydraulic drive unitsmounted in the window.

FIG. 19 is an enlarged scale fragmentary view of the left end portion ofFIG. 2, showing the connection of one of the movable slats to aconnector member on its drive beam; and

FIG. 20 is an enlarged scale view of one of the fixed slats and the sideportions of the movable slats on the opposite sides of the fixed slat.

FIG. 21 is an end view of a modified embodiment of the bearing, suchview being an end view of an extrusion;

FIG. 22 is an end view of a movable slat between and mounted onto twoadjunct fixed slats, showing the use of the bearing of FIG. 21;

FIG. 23-24 are views of three additional embodiments of the fixed slatswhich are in the nature of aluminum alloy extrusions; and

FIGS. 26-28 are end views of fixed slats of a composite constructionmade up of steel members that are welded together and to a supportstructure for the fixed slats.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

U.S. Pat. No. Re 35,022, granted Aug. 22, 1995, to Raymond Keith Foster,and entitled Reduced Size Drive Frame Assembly For A Reciprocating SlatConveyor, discloses a reciprocating slat conveyor in which the conveyorslats are connected to transverse drive beams which are in turnconnected to linear hydraulic motors. The linear hydraulic motors movethe drive beams and dive beams move the conveyor slats that areconnected to them.

The conveyor of this invention comprises a plurality of laterally spacedapart, longitudinally extending, fixed slats 10 and a plurality oflaterally spaced apart, longitudinally extended, movable slats 12,between the fixed slats 10. The fixed and movable slats 10, 12 extendsubstantially the full length of the conveyor. By way of typical andnon-limitive example, the conveyor length may be between 32 feet and 53feet.

Referring to FIG. 11, the fixed slats 10 are in the form of a tubularbeam, or “box” beam. Slats 10 have a top comprising a center portion 14and two side portions 16, 18. Below the top, a pair of laterally spacedapart side walls 20, 22 extend downwardly from where the side portions16, 18 of the top meet the center portion 14 to a bottom 24 thatinterconnects the lower boundaries of the side walls 20, 22. The sideparts 16, 18 of the top are in the nature of a pair of wings 16, 18 thatextend outwardly and slope upwardly from the locations 26, 28 where theymeet the side walls 20, 22 and the central portion 14.

The wings 16, 18 are adapted to receive and hold bearings 30 that aresubstantially U-shaped in cross section. Referring to FIG. 9, eachbearing 30 has an upper portion 32, a lower portion 34 and a bightportion 36 which interconnects the upper and lower portions 32, 34.Bearings 30 are elongated and each may include a sloping longitudinaledge surface 38. FIG. 9 shows a bearing 30 in a relaxed condition. Thewings 16, 18 preferably include a plurality of teeth 18 which slopedownwardly and inwardly on their outer sides and are slightly undercuton their inner sides. A bearing 30 is installed by moving the openthroat of the bearing 30 between parts 32, 34 towards the outer ends ofits wing 16, 18. When the sloping surface 38 meets the sloping outersurfaces of the teeth 18, the bearing 30 will be cammed onto the wing16. When the edge 38 of bearing 30 moves inwardly beyond the inner mostteeth 18 the lower part 34 of the bearing 30 will clamp itself on to thewing 16, 18. The teeth 18 will dig into the inner portion of the bearingpart 34, such as shown by FIG. 10. The engagement of the tooth 18 withthe bearing portion 34 will help secure the bearing 30 on the wings 16,18.

The fixed slats 10 may be one continuous member or they may be asuccession of sections positioned end-to-end on the conveyor frame. Inlike fashion, the bearings 30 may be a continuous member or may beshorter sections that are positioned end-to-end on the wings 16, 18.FIG. 10 shows the spring energy in the bearing acting to clamp thebearing 30 onto the side wing 16, 18, causing the teeth 18 to dig intothe lower part 34 of the bearing 30.

FIG. 3 shows an enlarged scale end view of the movable conveyor slat 12shown in FIGS. 1 and 2. FIG. 4 is an end view of a modified movableconveyor slat 12′ which in most respects is like slat 12. The slats 12,12′ will now be separately described.

Referring to FIG. 3, the movable slat 12 has a top section 40 composedof side parts 42, 44 and a central part 46. As clearly shown by FIG. 3,the movable slat 12 has a laterally outwardly opening channel shapedportion on each of its sides. The side portions 42, 44 of the top 44form upper flanges 42, 44. The pair of webs extend downwardly from theupper flanges, 42, 44 to become a pair of lower flanges 52, 54.Outwardly opening channel spaces 56, 58 are defined by and between theflanges 42, 52 and 44, 54. The inner boundaries of the channel spaces56, 58 are closed by the webs 48, 50. Web 48 and flange 42 form adownwardly and outwardly extending hook on their side of the slat 12.Web 50 and flange 54 form a downwardly and outwardly extending hook ontheir side of the slat 12. The bottom surface of flange 42 and the topsurface of flange 52 slope downwardly as they extend outwardly. Insimilar fashion, on the opposite side of the slat 12, the lower surfaceof flange 44 and the upper surface of flange 54 slope downwardly as theyextend outwardly from the web 50. This results in the channel spaces 56,58 sloping downwardly and outwardly. In addition to forming the hooks,the webs 48, 50 and the flanges 52, 54 strengthen the slat 12 as astructural member.

As shown by FIGS. 9 and 10, discussed above, the bearings 30 are solidlyanchored on the wings 16, 18. The movable slats 12 are aligned with thechannel spaces 56, 58 and the bearings 30 when the bearings are on thewings 16, 18. Then, each movable slat 12 is moved endwise to slide itonto its fixed slat 10. The lower surfaces of the upper flanges or sideparts 42, 44 rest on the upper surfaces of the bearing parts 32. When amovable slat 10 is on its fixed slat 12, there is supporting contactbetween the lower surfaces of slat parts 42, 44 and the upper surfacesof bearing parts 32. The bight 36 of the bearing 30 is sidewaycontiguous the outer surface of the web 48. On the opposite side of theslat, the bight 36 is contiguous the outer surface of the web 50. Thelower part 34 of the bearing 30 is contiguous the upper surfaces of theflanges 52, 54. If the slat should slide sideways, the leading web 48,50 will contact the bight 36 of the bearing 30 of its side of the slat.If the slat 12 should move upwardly for any reason, its lower flange 52,54 will contact the lower surfaces of the bearing parts 34.

The fitting of the bearings 36 and the wings 42, 44 within the channelspaces 56, 58 result in mutual reinforcement of the fixed and movableslats 10, 12. This is particularly important in the region of a windowin the conveyor frame, described below. The fixed slats 10 are supportedforwardly and rearwardly of the window in the conveyor frame. In theregion of the window, the fixed slats 10 bridge over the window.Throughout their lengths, the movable slats 12 rest on and are supportedby the wings 16, 18 of the fixed slats 10. Each movable slat 12 isconnected to a transverse drive beam where it crosses over thattransverse drive beam in the region of the window. See U.S. Pat. No. Re35,022. The interlocking of the fixed and movable slats, where thebearings 30 and the wings 16, 18 fit within the channel spaces 56, 58,causes the conveyor slats to be sufficiently supported under essentiallyall conditions that arise during operation of the vehicle in which theconveyor is installed. The box beam construction of the fixed slats 10,and the trihedral construction of the movable slats 12, make the slats10, 12 functioning structural members. It also enables them to be madewith thin wall lightweight materials. For example, in preferred form,the fixed slats 10 and the movable slats 12 are extrusions made from asuitable aluminum alloy. Of course, they can be made of other metals andcan be made from various plastic and composite materials as well.

FIG. 18 is a bottom plan view of the conveyor frame. It comprises firstand second longitudinally extending side frame members 70, 72 extendingthe full length of the conveyor. The frame also includes laterallyspaced apart longitudinally extending inside frame members 74, 76. Framemember 74 is spaced laterally inwardly from side frame member 70. Framemember 76 is spaced laterally inwardly from side member 72. The conveyorframe further comprises longitudinally spaced apart transverse framemembers 78, 80 which define between them a window in the conveyor framein which three transverse drive beams 82, 84, 86 are situated. Drivebeam 82 is connected to the moveable portion of a first drive unit 88.Drive beam 84 is connected to the movable portion of a second drive unit90. Drive beam 86 is connected to the movable portion of a third driveunit 92. As is known, the drive units 88, 90, 92 are operated to movethe drive beams 82, 84, 86 back and fourth lengthwise of the conveyor.Slats 1, 4, 7, 10 etc are connected to drive beam 82. Slats 2, 5, 8, 11,etc are connected to drive beam 84. The remaining floor slats areconnected to drive beam 86. See U.S. Pat. No. 35,022 for a preferred wayof making the connection. The drive units 88, 90, 92 have fixed portionsthat are connected to transverse frame members 94, 96 which extendlaterally between the longitudinal frame beams 74, 76. See theaforementioned

The window in which the drive beams 82, 84, 86 are situated is definedlongitudinally between the transverse frame members 78, 80 and isdefined in the transverse direction by and between the longitudinal sidebeams 70, 72. In the forward section of the conveyor, forwardly of thewindow, there are a plurality of longitudinally spaced apart transverseframe members 100. In like fashion, in the rear portion of the frame,rearwardly of the window, there are additional longitudinally spacedapart transverse frame members 100.

The transverse drive beams 82, 84, 86 are moved longitudinally of theconveyor frame and the window by the three drive units, 90, 92, 94. Whenthe movable portions of the drive units 90, 92, 94 are moved together,the transverse drive beams 82, 84, 86 are moved together and the movableconveyor slats 12 are moved together. Any load that is on the slats 12will be moved in the conveying direction. When the drive units 90, 92,94 have reached the ends of their drive strokes, the drive unitconnected to the trailing drive beam is retracted. This retracts a firstdrive beam and the conveyor slats that are connected to it. Theremaining movable conveyor slats, representing two thirds of the total,are stationary. They hold the load while the retracting slats are beingslid back under the load to the start position. When the first driveunit is fully retracted, the next drive unit is retracted, retractingwith it a second one third of the conveyor slats 12. These retractingconveyor slats slide rearwardly under the load back to a start position.As before, the load is held against movement by the stationary slatswhich subject the load to twice as much area as a retracting slats. Whenthe second drive unit is fully retracted, its conveyor slats are stoppedand the third and last transverse drive beam is retracted by its driveunit. This returns the remaining one third of the movable conveyor slatsback to their start position.

The fixed conveyor slats 10 are connected to the transverse framemembers 78, 80, 100 in the forward and rearward sections of the conveyorframe, e.g. by welding. The portions of the fixed slats that are abovethe window span the window from transverse beam 78 to transverse beam80. The movable slats 12 are supported by and travel on the fixed slats10. In the window region the movable slats are connected to thetransverse drive beams 82, 84, 86. By way of example, FIG. 2 shows thatone third of the movable slats 12 are connected to their drive beam bybolts which extended downwardly through the tops of the slats into alongitudinally extending connector member on the drive beam. See U.S.Pat. No. Re 35,022.

FIG. 4 shows an end view of a modified movable conveyor slat 12′.Conveyor slat 12′ is basically like conveyor slat 12, differing only inthat it is provided with a pair of laterally spaced apart, upwardyprojecting, longitudinal ridges 110, 112. The ridges 110, 112 have flatupper surfaces which are within a common plane that is above the uppersurface of the center portion 46′. In use, loads on pallets, and similarother loads having flat bottoms, set down on the tops of the ridges 110,112. The area of the retracting slats that must be slid under the loadis the combined area of the tops of the ridges 110, 112 of theretracting slats. The presence of ridges 110, 112 also helps make themovable slats 12′ less flexible, reducing any tendency that they mayhave to sag in the window region of the conveyor frame.

Referring to FIGS. 5 and 6, the rear of the conveyor frame is in theform of a transverse frame beam 114 having a top 116. As shown by FIG.5, the rear ends of the fixed slats 10 rest on the forward edge portionof the top 116. As also shown by FIG. 5, the front to rear dimension ofthe top 110 is preferably substantially equal to the stroke length ofthe movable slats 12. FIG. 5 shows the rear end of one slat 12substantially at the forward end of the beam 114 and the rear end of asecond slat 12 substantially at the rear end of the beam 114. The firstslat 12 is in a forward position. The second slat 12 is in a rearwardposition.

Preferably, a guide member 118 is provided for each slat 12. Each guidemember 118 extends longitudinally of the conveyor and is in line with atunnel opening in its conveyor slat 12. By way of typical andnon-limitive example, the guide members 118 may be lengths of bar stock118, e.g. one inch by one inch. As shown by FIG. 5, the rear end of eachguide beam 118 is adjacent the rear end of rear end beam 114. Theforward end portion of each guide member 118 projects forwardly a shortdistance from the forward end of the top 116.

As shown by FIGS. 13 and 14, a guide block 120 is provided to fit withinthe rear end portion of each movable slat 12. Guide block 120 has anupper portion sized to fit between the webs 48, 50 of the slats 12 and alower portion which extends downwardly and laterally outwardly below thelower flanges 52, 54. Each block 120 includes a tunnel opening 126 sizedto receive a guide member 118. As shown by FIGS. 5 and 6 together, thelength of each guide member 120 is preferably slightly longer than thewidth of the top 116 of beam 114. FIG. 5 shows that the rearward end ofthe block member 120 on the fully extended slat 12 is substantially atthe rear edge of the beam 114. FIG. 6 shows that the forward end of thesame member 120 is at the same time a short distance forwardly of theforward end of the beam 114. Preferably, the guide blocks 120 areconstructed from a self-lubricating plastic material (e.g. UHMW) so thatthere is a reduced friction where their surfaces contact and slide alongthe guide members 118.

As shown by FIG. 15, the rear ends of the fixed slats 10 may be closedby an end wall 128 shaped to fit rearwardly of the bearings 36, thewings 16, 18 and the center portion 20, 22, 24. If the end walls 128 areconstructed from thin metal, they may be welded to the ends of the fixedslats 10. If they are constructed from a plastic material, they may bebonded to the ends of the slats 10.

Referring to FIGS. 5 and 8, a granular material guiding member 130 maybe positioned on the top 116 of the rear beam 114 in axial alignmentwith each fixed slat 10, as shown in FIG. 8. As shown by FIG. 5, thegranular material guiding members 130 are substantially equal in lengthto the front-to-rear dimension of top 116. These members may be madefrom short lengths of metal having a uniform cross sectional shape suchas the angle shape shown by FIGS. 8 and 17. Angle members 130 have alongitudinal crown 132 and side parts 134, 136 which slope downwardlyand outwardly from the crown 132 to lower edges 138, 140. These members130 may be welded to the top 116 where their edges 138, 140 meet the top116. In FIG. 16, the spread angle X of the side members 134, 136 isshown to be a little greater than ninety degrees (90°). As shown by FIG.8, the height of the members 130, in the region of the crown 132, placesthe crown 132 substantially at the level of the upper surface of thefixed conveyor slat 10 where the crown 132 meets the conveyor slat 10.The base width of the member 130 places its lower edges 138, 140substantially in alignment with the side walls 20, 22 of the fixed slat10.

As can be appreciated, when the movable slats 12 are being movedrearwardly, with a load on them, the region between adjacent slats 12above the members 130 will be moved into positions above the crowns 132.When the slats 12 are retracted to a forward position, bulk material onthe upper surfaces of the side parts 42, 44 of the slats 12 will slidesideways onto the members 132 and will then slide to one side or anotherof the members 32, generally into the paths of the rear ends of themovable slats. Then, during the next conveying stroke, when the movableslats 12 are advanced to the rear of the conveyor, the rear ends of theslats 12 will push the bulk material rearwardly along and then off fromthe top 116.

FIG. 2 shows that on the two sides of the conveyor the fixed slats 150may have a different cross sectional shape than the other fixed slats10. This shape is shown by FIG. 12. Fixed slat 150 has a longitudinallyextending box beam section 152, a single wing 154, and a sloping guidepanel 156. The box beam section is anchored to the conveyor frame,placing the wing 154 in position to function the same as a wing 16. Wing154 is provided with a bearing 30 that fits on the wing 16, in themanner shown by FIG. 10. This wing 154 and its bearing 30 then fitwithin the channel space 58 on the outermost movable slat 12 on its sideof the conveyor. The sloping guide surface 156 slope upwardly andoutwardly from box beam 122 to a side wall portion of the installationwhere it is preferably connected to the side wall portion of theinstallation.

Preferably, the fixed and movable slats 10, 12 are extrusions made froma structural aluminum alloy. However, in some installations, the slats10, 12 can be constructed from other metals (e.g. steel) or from plasticor composite materials.

Referring to FIGS. 19 and 20, the movable slats 12 have a substantiallyhorizontal center portion 46 which is located between sloping sideportions 42, 44. As best shown by FIG. 20, the lower surfaces of theside portions 42, 44 sit down on the upper surfaces of the top parts 32of the bearings 30. The top surfaces of the bearing parts 32 and thelower surfaces of the slat parts 32, 44 are substantially planarsurfaces, each of which slopes upwardly and outwardly from its lowerend. As shown in FIG. 20, the slope angle of the surfaces is preferablybetween 18 degrees and 25 degrees. As a result, the V-angle between thetwo upper surfaces of the bearings 32 and between the two lower surfacesof the slat parts 42, 44 is about 130 degrees-144 degrees. The conveyorshown by FIGS. 1 and 2 is eighteen movable slats wide it includesnineteen fixed slats. A fixed slat 150 is on each side of the conveyorand seventeen fixed slats 10 are between adjacent movable slats 12. Thisarrangement provides nineteen trough spaces in which liquid can becollected. This liquid may be drainage from garbage carried by theconveyor. In this conveyor, the liquid is collected in the shallowV-region over the fixed slats 10, 150 and between the movable slats 12.In this conveyor, the bearings 30 also function as seals. The weight ofthe load acting downwardly on the moveable slats 12 presses the sideparts 42, 44 against the upper surfaces of the bearing parts 32. As canbe seen by FIG. 20, this surface contact is relatively wide and itslopes upwardly from the lower ends of the bearing parts 32 to the upperends of the bearing parts 32 where they meet bight 36. Moisture and orfines collected in the trough must move outwardly and upwardly betweenthe contacting surfaces before the moisture or fines can move intospaces below the movable slats. The weight of the load acting on themoveable slats 12, presses the side parts 42, 44 downwardly against theupper parts 32 of the bearings 30 and this contact essentially closesany passageway which might otherwise exsist between the side parts 42,44 of the movable slats 12 and the upper parts 32 of the bearings 30.Another feature of the movable slats 12 is that the central region 46has a substantially flat top 40. This flat region provides a largeramount of friction between the movable slats and the load in comparisonwith the V-slats that have rounded crowns at the centers, such as shownby the aforementioned U.S. Pat. No. 5,044,870.

The movable slats 12′ shown by FIG. 4 are constructed to withstand highimpact loads, e.g. a load imposed by heavy articles dropped onto a slat12′. FIG. 21 shows a bearing which may be used with the impact floor.FIG. 22 shows the bearing assembled with the fixed slats and the movablehigh impact slats 12′. A downward force imposed on the slat 12′ willmove the side parts 42′, 44′ of the slat 12′ against the upper part 32of the bearing 30. Some of this impact load may be transmitted by theflanges 52, 54 to the lower region 31 of the bearing 30′. This lowerregion 31 of the bearing 30′ sits down on the support surface(s) for thefixed slats 10.

FIGS. 23-28 show modified constructions of the fixed slats. The Fixedslats shown by FIGS. 22-24 are aluminum alloy extrusions. The fixedslats shown by FIG. 23 are longitudinal sections of a leakproof subdeckwhich includes a sealed connection between the adjacent side edges ofthe subdeck sections.

The fixed slats shown by FIGS. 24 and 25 have support legs that caneither be bolted down or welded to the support structure provided forsuch slats. The fixed slats shown by FIGS. 26-28 are made of stealmembers that are welded together and to the substructure below the fixedslat. In FIGS. 24-28, the wings are designated W.

The illustrated embodiments are only examples of the present inventionand, therefore, are non-limitive. It is to be understood that manychanges in the particular structure, materials and features of theinvention may be made without departing from the spirit and scope of theinvention. Therefore, it is our intention that our patent rights belimited by the particular embodiments illustrated and described herein,but rather are to be determined by the claims which follow, interpretedin accordance with the established rules of patent claim interpretation.

1. A reciprocating slat conveyor comprising a conveyor frame including apair of laterally spaced apart, longitudinally extending, side beams, aforward frame section comprising forward portions of the side beams andlongitudinally spaced apart lateral frame members extending between theside frame beams, a rearward frame section comprising rearward portionsof the side beams and longitudinally spaced apart lateral frame beamsextending between the side beams, and a window longitudinally betweenthe forward frame section and the rearward frame section, said windowproviding a space laterally between intermediate portions of the sidebeams and longitudinally between two longitudinally spaced apart lateralframe members; a plurality of drive units in the window, each having afixed portion anchored to the frame and movable portions moveable in thewindow; a plurality of transverse drive beams in the window, eachconnected to the movable portion of a different one of the drive units;a plurality of laterally spaced apart, longitudinally extending, fixedslats connected to the forward and rear sections of the frame andbridging longitudinally over the window and over the transverse drivebeams in the window; a plurality of laterally spaced apart,longitudinally extending, movable conveyor slats between the fixedslats, said movable slats being divided into sets equal in number to thenumber of transverse drive beams, and each set of movable slats beingconnected to a separate one of the transverse drive beams; and theimprovement comprising: said fixed slats each having a longitudinallyextending center portion and a pair of side wings extending laterallyoutwardly and upwardly from the center portion; said movable slats eachhaving a longitudinally extending center portion, a pair oflongitudinally extending side portions, and a pair of laterally spacedapart, longitudinally extending hook portions including a web connectedto the movable slat where the center portion meets a side portion, saidhook portions each extending first downwardly in the form of a web andthen laterally outwardly in the form of a lower flange that is integralwith the web, said slat side portions, said webs and said lower flangestogether forming laterally outwardly opening channel spaces; fixedbearings on the side wings each having an upper part sitting down on itsside wing and a lower part below its side wing said bearings beingmounted on said wings and said wings and bearings being located in thechannel spaces, vertically between the side portions of the slat and thelower flanges; and said side portions of the movable slats having bottomsurfaces which rest on the upper parts of the bearings, and said lowerflanges being below the lower parts of the bearings.
 2. Thereciprocating slat conveyor of claim 1, wherein the fixed and movableslats are extrusions, each having a uniform cross sectional shapethroughout its length.
 3. The reciprocating slat conveyor of claim 1,wherein in the forward and rearward frame sections, the center portionsof the fixed slats are connected to the lateral frame members.
 4. Thereciprocating slat conveyor of claim 1, wherein said conveyor frameincludes a rear frame beam extending transversely of the trailer, saidrear frame beam including a top, and wherein the movable slats have rearend portions which reciprocate forwardly and rearwardly over the topduring operation of the conveyor, and wherein said rear end portions ofthe movable slats include blocks within the rear end portions of themoveable slats, between the webs of the hook portions of the movableslats; said blocks each including a longitudinally extending, downwardlyopening channel space; and longitudinally extending guide memberssecured to the top of the rear frame beam, said guide members beingpositioned to be received in the channel spaces of the blocks, whereinthe blocks will slide forwardly and rearwardly along the guide membersduring movement of the movable slats.
 5. The reciprocating slat conveyorof claim 4, further comprising a rear frame beam having a top, materialguide members on the top of the rear frame beam, in longitudinalalignment with the fixed conveyor slats, said guide members each havinga longitudinally extending apex and longitudinally extending side wallssloping laterally outwardly and downwardly from the apex.
 6. Thereciprocating slat conveyor of claim 1, further comprise material guidemembers on the top of the rear frame beam, in longitudinal alignmentwith the fixed conveyor slats, said members having a longitudinallyextending apex and side walls sloping laterally and outwardly downwardlyfrom the apex.
 7. The reciprocating slat conveyor of claim 1, furthercomprising a transverse rear frame beam having a top, wherein saidmovable slats reciprocate back and fourth across the top; longitudinallyextending guide members secured to the top in substantial alignment withthe movable slats; and said movable slats including guide bearings andrear end portions of the movable slats which are positioned to receivethe guide members.
 8. The reciprocating slat conveyor of claim 7,wherein the fixed slats have rear end portions that terminate on aforward portion of the top of the transverse rear frame beam, andmaterial guide members on the top of the rear frame beam, inlongitudinal alignment with the fixed conveyor slats, said guide membershaving a longitudinally extending apex and longitudinally extending sidewalls sloping laterally outwardly and downwardly from the apex.
 9. Thereciprocating slat conveyor of claim 1, wherein the center portions ofthe fixed slats are tubular box beams having a width dimension greaterthan twice the height dimension where the side wings are attached to thecenter portion.
 10. The reciprocating slat conveyor of claim 9, whereinthe forward and rearward frame sections, the center portions of thefixed slats are connected to the lateral frame members.